The invention relates to an alignment device for motor vehicles.
The present invention is a system used for adjusting and measuring the track of a motor vehicle""s wheels. The system includes a telescoping bar, which is adjustable in length and includes a spring that functions as a accumulator. The two opposing ends of the telescoping bar exert expansion forces on either the two front wheels or the two rear wheels of a vehicle. Such a system, also designated as a track pusher, exerts a specific initial stressing force, for example 100 N onto the vehicle""s wheels. However, in known systems, a mechanical spring, in particular a compression spring, serves to produce the initial stressing force onto the wheels. In conventional systems where attempts have been made to measure several different vehicles that include different vehicle track widths, the strokes of the mechanical spring may produce imprecise and divergent expansion forces.
Thus, an objective of the invention is to create a system for adjusting the track on the wheels of a motor vehicle, in which a constant expansion force is supplied throughout the stroke.
One embodiment of the invention includes a pneumatic spring that serves as an accumulator. This embodiment includes a pneumatic spring housing and a piston rod telescoping axially out of the pneumatic spring housing with a certain force, e.g. 100 N. The pneumatic spring slidably attaches to the piston rod, which includes two attachment points that connect to a telescoping bar. Furthermore, during the stroke of the piston rod""s as it moves out of the pneumatic spring housing, an axial guiding arrangement of the telescopically adjustable bar supports the piston rod radially. In this manner, the invention guarantees that forces acting on the relatively thinly-designed piston rod act only in the axial direction, in which the spring force is essentially transferred.
During operation, one end of the pneumatic spring housing may be pressed against one wheel of the motor vehicle, for example, the left front wheel. In this connection, the end of the housing forms one end of the telescoping bar. The free end of the piston rod may be attached and/or supported on the bar-shaped guiding arrangement designed, in particular, as a tube. The pneumatic spring housing may be guided axially by a certain stroke exerted, for example, by on one end of the guiding arrangement. The other end of the guiding arrangement, which forms the other end of the telescoping bar, may be pressed against the other wheel of the motor vehicle, for example, the right front wheel.
In addition, several embodiments of the invention are possible in which the pneumatic spring housing supports a pneumatic spring within a guiding arrangement. The guiding arrangement may be supported against one wheel of the motor vehicle with an end portion that forms an end of the telescoping bar. The piston rod connects to an end of the telescoping bar so that support against the other wheel may be achieved. For instance, the piston rod may connect directly with one end of the telescoping bar, whereby the piston rod may be supported radially against the guiding arrangement during its axial movement or so that the end of the telescoping bar has one or more guide parts that may slide axially on the guiding arrangement.
The guiding arrangement may be designed tubular, so that the guiding arrangement supports the pneumatic spring housing, which mounts inside the tubular guiding arrangement.
The embodiments of the invention ensure that a constant initial stressing force, for example of 100 N, is exerted over the entire range of track width.